Question

A marble block of mass 2kg lying on ice when given a velocity of $6m{s}^{-1}$ is stopped by friction in 10s. Then the coefficient of friction is

• A. 0.06
• B. 0.02
• C. 0.01
• D. 0.03

Answer 1

The correct option is A 0.06

Given,

u = 6 m/s t = 10 s g = 10 m/s²

The block comes to rest in 10 seconds,

=> v = u + at

0 = 6 + a * 10

=> a = -0.6 m/s²

Net retarding force acting on the block = | ma | = 2*0.6

The block comes to rest due to friction.

=> friction on the block = 2*0.6

µN = µmg = 2*0.6

=> µ*2*10 = 2*0.6 or µ = 0.6/10

µ = 0.06